Two Vintage GM Inline-Six Exhaust Manifolds

-Two cast-iron exhaust manifolds for inline six-cylinder engine applications
-Both display GM casting marks
-Manifolds have similar four-port layouts but differ in casting shape and outlet configuration
-One retains an exhaust-pipe flange section at the outlet
-Visible casting numbers are weathered and cannot be read with enough certainty to confirm exact vehicle, year or engine application